This invention relates to generally to semiconductor devices and, more particularly to semiconductor stacked die constructions and methods of forming the same.
Semiconductor devices are typically constructed from a silicon or gallium arsenide wafer through a process involving a number of deposition, masking, diffusion, etching, and implanting steps. Usually, many individual devices are constructed on the same wafer. After fabrication, the wafer is typically sawed or otherwise singulated into individual units, where each unit takes the form of an integrated circuit (IC) die.
It has become a practice in the industry to provided integrated circuit devices in the form of so-called xe2x80x9cstacked diexe2x80x9d arrangements. Stacked die arrangements typically involve two or more IC die that are fixed upon one another, typically through some type of adhesive arrangement. Interconnections can then be made between the individual die to provide an overall device with a desirable density and enhanced functionality.
Examples of stacked die arrangements are described in detail in the following U.S. Patents, to which the reader is referred for additional detail: U.S. Pat. Nos. 5,291,061; 6,051,886; 5,397,916; 5,434,745; 6,093,939; and 5,864,177.
To date, interconnections between the individual die of stacked die arrangements have been made at or near the periphery of each die. U.S. Pat. Nos. 5,291,061, and 5,397,916 provide very good examples of this type of interconnection. As device processing speeds continue to increase, those involved in the design of semiconductor devices are necessarily forced to consider and reconsider traditionally accepted notions of circuit design. One particular area of interest in the industry concerns the design and fabrication of memory devices, and particularly those memory devices that employ stacked die arrangements.
Accordingly, this invention arose out of concerns associated with providing improved systems that employ stacked die arrangements, and methods of forming the same.
Semiconductor devices and methods of forming semiconductor devices are described. In one embodiment, at least one conductive structure is formed within a plurality of semiconductor substrates. At least portions of one of the conductive structures has oppositely facing, exposed outer surfaces. Individual substrates are stacked together such that individual conductive structures on each substrate are in electrical contact with the conductive structure on a next adjacent substrate.
In another embodiment, at least one conductive structure is formed within each of a plurality of semiconductor substrates. The conductive structures have oppositely-facing surfaces. Portions of each oppositely-facing surface are exposed on at least one of the substrates. The substrates are processed sufficient to form electrical connections between the substrates by stacking the substrates on one another so that the conductive structures on adjacent substrates are electrically connected.
In yet another embodiment, at least one multi-layered, conductive pad structure is formed within each of a plurality of semiconductor substrates. Each conductive pad structure has oppositely-facing surfaces. Portions of each oppositely-facing surface are exposed on at least one of the substrates. At least one such surface is exposed by etching portions of the substrate. After the oppositely-facing surface portions are exposed, additional conductive material is formed over and in electrical contact with the exposed surface portions by plating at least one additional conductive material over the exposed portions.
In still a further embodiment, a semiconductor device comprises a first semiconductor die comprising IC devices. At least one conductive structure is disposed within and through the first die and in operative contact with the IC devices. A second semiconductor die comprises IC devices, and is mounted together with the first die in a stacked arrangement. The second semiconductor die has at least one conductive structure disposed therewithin and in electrical contact with both the IC devices of the second semiconductor die and the conductive structure of the first semiconductor die.
In yet another embodiment, a semiconductor device comprises multiple semiconductor die, each of which comprising IC devices. At least one conductive structure is disposed generally in the center of each die. The multiple die are joined together in a die stack such that electrical contact between adjacent die is made through the conductive structures associated with each of the die.